Angular provides us with several filters which are useful formatting values inside our templates in a declarative way. The built-in filters are fairly useful, but the real power from filters comes from being able to write custom filters.
For example, we might want to write a pluralize filter, that works similar to the pluralize function in Rails.
Writing a custom filter is very simple - we simply call the
filter function and return another custom function. This function takes at least one parameter and returns a single value. All filters can take additional parameters which can further enhance their behavior.
In this case I am going to accept two parameters - the count and the text to be pluralized. The first parameter will be the value the filter is applied to and additional parameters will be specified as colon-separated values.
For example, in this template the first parameter will be 5 and the second parameter will be the string ‘apple’.
Here is what the actual filter looks like:
You can find the entire example on Plunker. Happy coding.